UK Wind Farm Curtailment Tracker
Ranked tracker of balancing-mechanism curtailment payments by asset, using Elexon BMRS data. Two widgets show the same market, at different stages of the settlement process.
About this data
Data source
Both widgets use publicly licensed data from Elexon's Balancing Mechanism Reporting Service (BMRS). The provisional widget reads BOALF (Bid-Offer Acceptance Level Flagged) data — near-real-time records of every dispatch instruction issued by the System Operator. The finalized widget reads BOAV (Acceptance Volumes by Settlement Date) — settled figures from Elexon's Initial Information Run.
Why two widgets?
Provisional data (Widget A) appears within minutes of a curtailment instruction and is useful for near-real-time monitoring, but volumes can change once Elexon runs settlement. Finalized data (Widget B) comes from the Initial Information Run (~5 working days after settlement) — the first point at which acceptance volumes are settled. The leaderboard and headline totals use only this finalized data to avoid publishing rankings based on figures that might later be corrected.
£ payment estimates
Actual curtailment payments equal accepted bid volume × the bid price offered by each generator. Bid prices are commercially sensitive and not individually published by Elexon in a simple per-unit format. The £ figures shown here are estimated using the Elexon system sell price as a proxy for bid prices. Actual payments may differ, sometimes significantly, where generators bid at prices well above or below the system price.
What is and is not included
This tracker covers only Balancing Mechanism-visible curtailment payments — bids accepted by the System Operator within the BM. It does not include private bilateral contracts between the System Operator and generators (e.g., constraint management contracts negotiated outside the BM). Those payments are not publicly disclosed and are therefore not represented here.
Update schedule
Provisional data refreshes every 20 minutes alongside Elexon system price data. Finalized data refreshes daily at 08:00 UTC, processing settlement dates from 10 to 35 days ago (safely past Elexon's Initial Information Run at ~5 working days). BMU asset metadata (names, regions) refreshes weekly.
Settlement timeline
Balancing actions are settled through six standard runs per settlement day (source: Elexon BSCP01): II (Interim Information, ~5 working days — first settled volumes, no payment); SF (Initial Settlement, ~16 working days — first payment, at ~29 calendar days); R1 (~2 months); R2 (~5 months); R3 (~7 months); RF (Final Reconciliation, ~14 months). A Dispute Final run (DF) can follow up to 28 months later in exceptional cases. Widget B uses II run data; BOA acceptance volumes are stable across runs. For authoritative settlement data, consult Elexon directly.